Pierce ranks anywhere from 5-8. What bodes well for him is that he is in the top 5 in many of the statistical categories but obviously in Boston players are rated via Championships. So another ring could really help ensure his legacy currently I think I would have him in the all time Celtics starting line up though that doesn't necessarily make you a top 5 Celtic.

Russell
McHale
Bird
Pierce
Cousy

Bench
Cowens
Heinsohn
Hondo
Jones
DJ
Garnett
Jo Jo White

Move Cowens and Jo Jo White above PP. PP would be behind even DJ if he wasn't saved by KG and Ray Ray.YOu need to add TIny and Parrish to this list also.